Tom and his little sister are enjoying an afternoon at the ice rink. They playfu
ID: 1467501 • Letter: T
Question
Tom and his little sister are enjoying an afternoon at the ice rink. They playfully place their hands together and push against each other. Tom's mass is 72 kg and his little sister's mass is 15 kg.
(a) Which of the following statements is correct?
A)The force experienced by Tom is less than the force experienced by his sister.
B)The force experienced by the sister is less than the force experienced by Tom.
C)They both experience the same force.
(b) Which of the following statements is correct?
A)Tom's acceleration is less than the sister's acceleration.
B)They both have the same acceleration.
C) Tom's acceleration is more than the sister's acceleration.
(c) If the sister's acceleration is 3.1 m/s2 in magnitude, what is the magnitude of Tom's acceleration?
_______m/s2
Explanation / Answer
1) C is the correct answer
As there is no external force, the force on tom = force on his sister ( Newton's third law of motion)
F= m*a
As F is identical and masses are different, then accelerations are also different.
2) Tom has high mass hnce less acceleration and vice versa for his sister in order to make product m*a identical for both
3) as = 3.1m/s^2, F= m*a = 15*3.1=46.5N
aT = 46.5/72 = 0.64583 m/s^2
MT = 72kg
MS = 15kg
According to conservation of momentum
0= MT*VT + MS*Vs => 72*VT + 15*Vs =0 => VT = -(15/72)*Vs